TermObjectifier

An Objectifier of Terms, implemented as a TermVisitor so that every Term sub-type is converted into a plain object following a fixed, format-agnostic scheme. This scheme is what lets a TermSerializer render any Term as JSON, YAML, or XML.

The scheme used by the platform-provided implementations (default) is, informally:

• a it.unibo.tuprolog.core.Var becomes {"var": "<name>"};

• an it.unibo.tuprolog.core.Atom becomes its String value (true/false for it.unibo.tuprolog.core.Truth.TRUE/it.unibo.tuprolog.core.Truth.FALSE, the atom "fail" for it.unibo.tuprolog.core.Truth.FAIL);

• a small it.unibo.tuprolog.core.Integer becomes a plain number, a larger one (that overflows a platform Long/Int) becomes {"integer": "<decimal string>"};

• a it.unibo.tuprolog.core.Real becomes {"real": "<decimal string>"};

• a it.unibo.tuprolog.core.Struct becomes {"fun": "<functor>", "args": [...]};

• a well-formed it.unibo.tuprolog.core.List becomes {"list": [...]}, a non-well-formed one additionally carries "tail": ...;

• a it.unibo.tuprolog.core.Block becomes {"block": [...]}, a it.unibo.tuprolog.core.Tuple becomes {"tuple": [...]};

• a it.unibo.tuprolog.core.Rule becomes {"head": ..., "body": ...}, a it.unibo.tuprolog.core.Fact becomes {"head": ...}, a it.unibo.tuprolog.core.Directive becomes {"body": ...}.

A TermDeobjectifier recognizes exactly this shape, so deobjectifier.deobjectify(objectifier.objectify(term)) round-trips (up to variable renaming and numeric literal formatting).

See also